For years the accepted state-of-the-art means for supplying digital magnetic tape to data processors and other users was the familiar 101/2 inch reel of ferric oxide magnetic tape. The development of the IBM 3480 Magnetic Tape Subsystem which utilizes a recording medium of chromium-dioxide magnetic particles on tape contained within compact, easy to handle cartridges, is rapidly making the 101/2 inch tape reels obsolete. Not only is the chromium-dioxide magnetic tape technologically better than ferric oxide tape, but being stored in specially designed cartridges which are about 4 inches by 5 inches in size compared with the 101/2 inch reels has resulted in substantial space saving to users.
Libraries for tape cartridges are available in the form of conventional stationary pigeon hole stacks into which individual cartridges are slid and then removed for usage. Portable carts with pigeon holes are also available to transport a number of cartridges from the stacks to the data processing equipment.
It is one of the objects of this invention to provide a magnetic tape cartridge storing and dispensing system which is not only space economical but also adapted to dispense cartridges from a storage position to one wherein cartridges may be removed with a minimum of effort and time.
Holders or dispensers for magnetic tape cartridges, or cassettes as they are also called, are in existence today. One example is found in U.S. Pat. No. 4,087,138 to MacRay which discloses a dispensing cabinet for tape cassettes having a plurality of pigeon hole slots, each of which is provided with its own ejector to push a cassette out of its pigeon hole to a position where the cassette may be gripped by hand.
A similar pigeon hole storage device is disclosed in U.S. Pat. No. 4,330,162 to Aboussouan. Similar to the MacRay device, Aboussouan employs an individual ejector mechanism in each pigeon hole to forcibly urge the cassette from its storage position to one where it may be picked out of the pigeon hole.
Both the MacRay and Aboussouan storage means require a plurality of moving parts as well as a separate pigeon hole for each cartridge and cassette. This results in a relatively expensive device which would be cost prohibitive to large users of magnetic tape cartridges. The systems also require storage area for many large stacks holding hundreds of cartridges each.
It is another object of this invention to provide a magnetic cartridge storing and dispensing device which eliminates the need for both a pigeon hole and an ejector for each cartridge and permits the storage of a greater number of cartridges in less space.
In, commonly owned, co-pending U.S. Pat. Application of Ronald R. King and Norman C. May, Sr., Ser. No. 729,364 filed May 1, 1985, for "System For Storage and Dispensing Magnetic Tape Cartridges", there is disclosed a system wherein there are a plurality of rows of pivotal storage cells within a frame. Each cell has a cartridge-discharge end and a cartridge-abutting end opposite each other. A support is located beneath the rows of cells and extends horizontally across the frame. Pivot means are located intermediate the ends of each cell to permit it to pivot on the support means relative to the horizontal. Means are provided to limit the amount of pivotal movement of the cell relative to the horizontal. In one embodiment of the invention the center of gravity of the cell is located closer to the cartridge-abutting end than to the cartridge-discharge end so that the bottom of the cartridge-abutting end of the cell normally occupies a lower position relative to the horizontal than the cartridge-discharge end, that is, the cell and the cartridge it contains tilts downwardly to the rear of the supporting means. Means are provided to limit the amount of downward pivotal movement of both the cartridge-discharge end and the cartridge-abutting end.
To remove a cartridge from the cell, the front or cartridge-discharge end is manually tipped downwardly to expose the upper front portion of the cartridge whereby it may be picked out of the cell. After the cartridge is removed, the weight of the cell tips it rearwardly into the position it occupied when it contained the cartridge.